From eb48e9fc0028bed94a40a9352d065909f19e333c Mon Sep 17 00:00:00 2001 From: Gwendal Grignou Date: Tue, 19 Nov 2024 22:25:22 -0800 Subject: [PATCH] scsi: ufs: core: sysfs: Prevent div by zero Prevent a division by 0 when monitoring is not enabled. Fixes: 1d8613a23f3c ("scsi: ufs: core: Introduce HBA performance monitor sysfs nodes") Cc: stable@vger.kernel.org Signed-off-by: Gwendal Grignou Link: https://lore.kernel.org/r/20241120062522.917157-1-gwendal@chromium.org Reviewed-by: Can Guo Signed-off-by: Martin K. Petersen --- drivers/ufs/core/ufs-sysfs.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c index 265f21133b633..796e37a1d859f 100644 --- a/drivers/ufs/core/ufs-sysfs.c +++ b/drivers/ufs/core/ufs-sysfs.c @@ -670,6 +670,9 @@ static ssize_t read_req_latency_avg_show(struct device *dev, struct ufs_hba *hba = dev_get_drvdata(dev); struct ufs_hba_monitor *m = &hba->monitor; + if (!m->nr_req[READ]) + return sysfs_emit(buf, "0\n"); + return sysfs_emit(buf, "%llu\n", div_u64(ktime_to_us(m->lat_sum[READ]), m->nr_req[READ])); } @@ -737,6 +740,9 @@ static ssize_t write_req_latency_avg_show(struct device *dev, struct ufs_hba *hba = dev_get_drvdata(dev); struct ufs_hba_monitor *m = &hba->monitor; + if (!m->nr_req[WRITE]) + return sysfs_emit(buf, "0\n"); + return sysfs_emit(buf, "%llu\n", div_u64(ktime_to_us(m->lat_sum[WRITE]), m->nr_req[WRITE])); }